Physics form 3&4_Most appeared critical angle questions in your exams [with answers]

1.Calculate the refractive index for water,given that the critical angle for water is 48.8°.[Ans.refractive index of water=1.33]
2.Given that the refractive index for a glass is 1.5,calculate the critical angle c for the glass.[Ans.c=41.8°]
3.A ray of light travels through air into another medium.Its angle of incidence is 70° and its angle of refraction is 22.8°.Calculate the critical angle c for the medium.[Ans.c=24.4°]
4.Calculate the critical angle for a light ray incident on a water-air boundary.Given that refractive index of water=4/3.[Ans.c=48.6066°]